• Asian-Australasian Journal of Animal Sciences
• /
• 제26권12호
• /
• pp.1680-1688
• /
• 2013

Many different approaches have been developed to improve the efficiency of animal cloning by somatic cell nuclear transfer (SCNT), one of which is to modify histone acetylation levels using histone deacetylase inhibitors (HDACi) such as trichostatin A (TSA). In the present study, we examined the effect of TSA on in vitro development of porcine embryos derived from SCNT. We found that TSA treatment (50 nM) for 24 h following oocyte activation improved blastocyst formation rates (to 22.0%) compared with 8.9% in the non-treatment group and total cell number of the blastocysts for determining embryo quality also increased significantly ($88.9{\rightarrow}114.4$). Changes in histone acetylation levels as a result of TSA treatment were examined using indirect immunofluorescence and confocal microscopy scanning. Results showed that the histone acetylation level in TSA-treated embryos was higher than that in controls at both acetylated histone H3 lysine 9 (AcH3K9) and acetylated histone H4 lysine 12 (AcH4K12). Next, we compared the expression patterns of seven genes (OCT4, ID1; the pluripotent genes, H19, NNAT, PEG1; the imprinting genes, cytokeratin 8 and 18; the trophoblast marker genes). The SCNT blastocysts both with and without TSA treatment showed lower levels of OCT4, ID1, cytokeratin 8 and 18 than those of the in vivo blastocysts. In the case of the imprinting genes H19 and NNAT, except PEG1, the SCNT blastocysts both with and without TSA treatment showed higher levels than those of the in vivo blastocysts. Although the gene expression patterns between cloned blastocysts and their in vivo counterparts were different regardless of TSA treatment, it appears that several genes in NT blastocysts after TSA treatment showed a slight tendency toward expression patterns of in vivo blastocysts. Our results suggest that TSA treatment may improve preimplantation porcine embryo development following SCNT.

• BMB Reports
• /
• 제48권12호
• /
• pp.685-690
• /
• 2015

The eukaryotic genome is packed into chromatin, which is important for the genomic integrity and gene regulation. Chromatin structures are maintained through assembly and disassembly of nucleosomes catalyzed by histone chaperones. Asf1 (anti-silencing function 1) is a highly conserved histone chaperone that mediates histone transfer on/off DNA and promotes histone H3 lysine 56 acetylation at globular core domain of histone H3. To elucidate the role of Asf1 in the modulation of chromatin structure, we screened and identified small molecules that inhibit Asf1 and H3K56 acetylation without affecting other histone modifications. These pyrimidine-2,4,6-trione derivative molecules inhibited the nucleosome assembly mediated by Asf1 in vitro, and reduced the H3K56 acetylation in HeLa cells. Furthermore, production of HSV viral particles was reduced by these compounds. As Asf1 is implicated in genome integrity, cell proliferation, and cancer, current Asf1 inhibitor molecules may offer an opportunity for the therapeutic development for treatment of diseases.

• BMB Reports
• /
• 제31권5호
• /
• pp.484-491
• /
• 1998

Acetylation of lysine residues within the aminoterminal domains of the core histones plays a critical role in chromatin assemhly as well as in regulation of gene expression. To study the biochemical function of histone acetylation, we have cloned a cDNA encoding the catalytic subunit of human histone acetyltransferase, Hat1. Analysis of the predicted amino acid sequence of human Hat1 revealed an open reading frame of 419 amino acids with a calculated molecular mass of 49.5 kDa and an isoelectric point of 5.5. The amino acid sequence of human Hat1 is homologous to those of known and putative Hat1 proteins from various species throughout the entire open reading frame. The recombinant human Hat1 protein expressed in bacteria possesses histone H4 acetyltransferase activity in vitro. Both RbAp46 and RbAp48, which participate in various processes of histone metabolism, enhance the histone acetyltransferase activity of the recombinant human Hat1, indicating that they are both able to functionally interact with the human Hat1 in vitro.

• 한국식품과학회지
• /
• 제12권4호
• /
• pp.263-271
• /
• 1980

피마자박 단백질을 사료 또는 식품화 하기 위하여 탈지 피마자박으로부터 독성분이 완전하게 제거된 단백질을 만들었다. 이 피마자 단백질의 용해도는 ${\varepsilon}$-아미노기의 숙시닐화 및 아세틸화로 $pH\;7{\sim}8$에서 현저하게 증가하였다. 아미노산 분석결과, 황-함유 아미노산과 L-리신이 제한 아미노산이었고, 아실화 과정은 아미노산 함량에 약간의 손실을 주었다. 파파인을 이용한 1 단계법 plastein 반응으로 피마자 단백질 또는 아실화 피마자 단백질과 DL-메티오닌 에틸 에스테르로부터 L-메티오닌 강화 피마자 단백질을 합성하였고, 이 방법으로 L-메티오닌 도입율은 50%였다. 피마자 단백질 및 수식된 피마자 단백질의 펩신에 의한 소화율은 모두 92% 정도였으나, 트립신에 의한 소화율은 숙시닐화 및 아세틸화 단백질이 현저하게 떨어져서 각각 42% 및 26%였다. 피마자 단백질의 단백질 효율은 L-메티오닌 강화로 카제인의 단백질 효율의 90%까지 향상되었으나, 피마자 단백질을 숙시닐화 및 아세틸화 하면 단백질 효율은 감소되어, 각각 카제인의 55% 및 69%였다.

• 생명과학회지
• /
• 제21권4호
• /
• pp.616-620
• /
• 2011

진핵세포의 크로마틴에서 히스톤 단백질 H3와 H4의 라이신 잔기는 공유결합에 의해 변형된다. 히스톤 H3에서 27번 라이신은 아세틸화되거나(H3K27ac) 세 가지 단계로 메틸화가 될 수 있으며(H3K27me1, H3K27me2, H3K27me3), 이러한 H3K27의 변형들은 각각 독특한 형태로 유전자 전사 및 크로마틴 구조와 관련된다. 일반적으로 H3K27ac과 H3K27me1은 좌위조절부위나 활발히 전사되는 유전자처럼 활성 크로마틴에서 나타나고, 이에 반해 전사가 일어나지 않은 유전자는 높은 수준의 H3K27me2과 H3K27me3이 관찰된다. 이러한 변형들은 각각 다른 종류의 변형효소에 의해 촉매된다. 최근 연구들은 유전자 전사 및 크로마틴 구조 형성에서 H3K27의 네 가지 변형들 사이에 상관 관계가 있음을 제시하고 있다.

• BMB Reports
• /
• 제52권10호
• /
• pp.619-624
• /
• 2019

The primary cilium is a microtubule-based structure projecting from a cell. Although the primary cilium shows no motility, it can recognize environmental stimuli. Thus, ciliary defects cause severe abnormalities called ciliopathies. Ciliogenesis is a very complex process and involves a myriad of components and regulators. In order to excavate the novel positive regulators of ciliogenesis, we performed mRNA microarray using starved NIH/3T3 cells. We selected 62 murine genes with corresponding human orthologs, with significantly upregulated expression at 24 h after serum withdrawal. Finally, calpain-6 was selected as a positive regulator of ciliogenesis. We found that calpain-6 deficiency reduced the percentage of ciliated cells and impaired sonic hedgehog signaling. It has been speculated that this defect might be associated with decreased levels of ${\alpha}-tubulin$ acetylation at lysine 40. This is the first study to report a novel role of calpain-6 in the formation of primary cilia.

• 한국식품조리과학회지
• /
• 제3권2호
• /
• pp.9-16
• /
• 1987

제사공장에서 부산물로 나오는 번데기는 단백질의 함량이 높을 뿐 아니라 필수 아미노산 조성도 우수하여 영양적으로 좋은 단백질원으로 알려져 있다. 이에 번데기로 농축단백질을 조제해서 무수초산과 호박산으로 아실화시켜 아미노산조성 및 주사전자현미경에 의한 관찰을 대두농축단백질과 비교 검토하여 다음과 같은 결과를 얻었다. 1. 번데기 농축단백질의 단백질 함량은 84.1%로서 대두농축단백질의 70.3%보다 높았다. 2. 번데기 농축단백질은 아미노산 조성에 있어서 대두농축단백질보다 필수 아미노산 함량이 높았으며 특히 대두에 부족한 methionine은 4.21(g/100g)로 매우 높았고, F.A.O.의 scoring pattern과 비교시 전체적으로 필수 아미노산이 함량이 높았다. 또한 번데기 농축단백질은 alanine, valine, phenylanine, isoleucine 등 지방족 아미노산의 함량이 높게 나타났다. 한편 변형번데기단백질에서는 아미노산의 함량에 약간의 손실을 가져왔으며 숙시닐화에서 더 큰 경향을 나타내었고 특히 lysine의 함량이 현저하게 감소되었다. 3. 주사전자현미경에 의한 관찰에서 탈지번데기분은 작고 입자가 많이 모여 하나의 agglomerate의 형태로 거칠고 세포성이 그대로 보존되어 있다. 기포의 생성이 많았으며 입자가 불균일(10~$20\mu{m}$)하였다. 번데기 농축단백질은 탈지번데기분보다 세포성이 많이 파괴되어 기포의 생성도 적어 입자의 표면적이 어느정도 넓고 부드러웠다. 또한 변형번데기농축단백질에서는 현저하게 세포성이 파괴되고 가 감소하여 좋은 조직을 형성하였으며 특히 숙시닐화한 단백질에서는 아주 부드럽고 좋은 조직을 나타내었다.

• 한국식품조리과학회지
• /
• 제3권2호
• /
• pp.1-8
• /
• 1987

번데기 농축단백질을 무수초산 및 호박산으로 숙시닐화 및 아세틸화시켜, 식품단백질원으로 이용가능성을 검토하기 위해 몇가지 중요한 기능성을 측정하여 다음과 같은 결과를 얻었다. 1. 번데기농축단백질이 아세틸화율은 82.0%, 숙시닐화율은 88.0%였으며, 아실화되는 과정에서 번데기 농축단백질은 밝은 상아빛으로 부드러웠으며, 특유한 냄새도 제거되었다. 2. 번데기 농축단백질은 pH 5.0에서 최소의 용해도를 나타내었으나 에세틸화 및 숙시닐화한 단백질은 pH 4.5에서 최소를 나타내었으며, 아실화에 의하여 용해도가 증가되었고 특히 숙시닐화는 약5배의 증가를 보였다. 3. 번데기 농축단백질의 겉보기 밀도와 수분흡수력은 아세틸화와 숙시닐화에 의해서 높은 증가를 나타내었다. 4. 번데기 농축단백질이 유화활성, 유화안정성, 유화용량은 아세틸화한 단백질에서는 유의성이 인정되지 않았으나 숙시닐화한 단백질은 높은 유의성을 나타내었다. 5. 번데기 농축단백질의 포말성은 숙시닐화한 단백질에서 30%의 증가 현상을 나타내었으며 포말안정성은 아세틸화 및 숙시닐화에 의해서 3시간, 8시간으로 향상되었다. 6. 각 농도별 점도는 아세틸화한 단백질에서는 별 영향이 없었으나 숙시닐화는 점도가 많이 증가되었으며 4∼5%에서 증가 현상이 가장 크게 나타났다.

• 식물조직배양학회지
• /
• 제24권1호
• /
• pp.1-35
• /
• 1997

Fertilized egg, by successive cell divisions, differentiates into different tissues and organs with various structures and functions. Different cells and tissues contain different proteins, products of selective gene expression. Not all the genes in any genomes are equally active, temporal and spatial gene expression being the general rule. Present paper attempts to review the tanscriptional mechanisms or the initiations of transcription from several angles. In some of the organisms the genes in the process of transcription or the genes in the inactive state can be seen under the light microscope. Some bands of Drosophila polytene chromosomes may exhibit a swollen or puff appearance under certain conditions. A puff, unfolded or decondensed form of chromomere, represents sets of intense transcriptional activity or RNA synthesis. The heterochromatic X chromosome whose genes remain inactive in the female mammals can be visualized as a dark staining structure called Barr body, Configuration of chromatin differs between transcribed and nontranscribed chromatin. Modification to the chromatin facilitates RNA synthesis. The movement of large polymerase molecule along the DNA would probably be facilitated if some modifications of the chromatin configuration is effected. Methylation of cytosines in CG sequences is associated with inactive genes. Methylation can play a role in determination of mammalian cells during embryogenesis. Demethylation is necessary for the gene to be expressed during development A histone modification that is also known to be correlated with transcriptional capacity of chromatin is acetylation of the lysine residues of the core histones. Chromatin containing a high level of histone acetylation is very sensitive to DNase 1. For the transcription to occur TBP must first bind to the TATA box. Another TF, TF IIB, then binds to the promoter-TBP complex, facilitating the access of RNA polymerase to the transcription initiation site. As recently as eight years ago researchers assumed that histones were irrelevant to the regulation of gene expression. Histones combine with the DNA to form nucleosome of the chromatin. Histones are vital participant in gene regulation. Histone and basal factors compete for access to TATA box. When DNA is exposed to basal factors before histones are introduced, the basal factors assemble on TATA boxes preventing the access of histones, allowing transcription to occur, for transcription to begin, activator protein at the upstream activation sequence or enhancer must interact with the tail of histone H4 at TATA box and cause the histone role particle to dissociate from the TATA box leading to partial breakup of the histone core particle and allowing the basal factors to bind to the TATA box. New concept of genomic flux in contrast to the old concept of static genome has been developed based on the powerful new molecular techniques. Genomic changes such as repetitive DNAs and transposable elements, it is assumed but not yet proved, may affect some of the developmental patterns that characterize particular cells, tissues, organs, and organisms. In the last decade or so remarkable achievement have been made in the researches of the structures and functions of TFs and the specific target sequences located in promoters or enhancers where these TFs bind. TFs have independent domains that bind DNA and that activate transcription. DNA binding domain of TFs serves to bring the protein into the right location. There are many types of DNA binding domains. Common types of motifs can be found that are responsible for binding to DNA. The motifs are usually quite short and comprise only a small part of the protein structure. Steroid receptors have domains for hormone binding, DNA binding, and activating transcription. The zinc finger motif comprises a DNA binding domain. Leucine zipper consist of a stretch of amino acids with a leucine residue in every seventh position Two proteins form a dimer because they interact by means of leucine zippers on similar α-helical domain. This positions their DNA binding basic domains for interaction with the two halves of a DNA sequence with dyad symmetry of TGACTCA, ACTGAGT.